Apple scab first appears as small, olive-colored lesions on the undersides of the leaves. As the fungus spreads, the top sides of the leaves develop lesions, as well, that may become black or mottled with defined edges. Severely infected trees may become defoliated by mid-summer, making the tree vulnerable to other diseases. The fruit develop black or brown scabs or soft areas.
cytosis. [ 1 sÄ«tÅâ²sis] 2  a condition in which there is a greater than normal number of cells in a tissue or organ.
Phagocytosis (phago-cyt-osis) - a process that involves the engulfing of a cell or particle. Macrophages are examples of cells that engulf and destroy foreign substances and cell debris in the body. Thrombosis (thromb-osis) - a condition that involves the formation of blood clots in blood vessels.